Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-26T09:34:49.889Z Has data issue: false hasContentIssue false

Oil migration makes the difference: regional distribution of carbonate cement δ13C in northern North Sea Tertiary sandstones

Published online by Cambridge University Press:  09 July 2018

C. I. Macaulay*
Affiliation:
Isotope Geosciences Unit, Scottish Universities Research & Reactor Centre, East Kilbride G75 0QF
A. E. Fallick
Affiliation:
Isotope Geosciences Unit, Scottish Universities Research & Reactor Centre, East Kilbride G75 0QF
R. S. Haszeldine
Affiliation:
Department of Geology & Geophysics, Grant Institute, University of Edinburgh, Edinburgh EH9 3JW
G. E. McAulay
Affiliation:
Department of Geology & Applied Geology, University of Glasgow, Glasgow G12 8QQ, UK

Abstract

Carbonate cements in Tertiary reservoir sandstones from the northern North Sea have distinctive carbon isotopic compositions (δ13C). Oil migration up faults from deeper structures and biodegradation of oil pools are factors of particular importance in influencing the δ13C of carbonate cements in these sandstones. As a result, δ13C can be used as an exploration guide to locating the positions of vertical leakoff points from the Jurassic source rocks. The histogram distribution of δ13C in these carbonate cements is trimodal, with peaks at around −26, −3 and +12‰ (ranges −22 to −30, +2 to −10 and +8 to +18‰, respectively). Bacterial processes played major roles in determining this distribution, with oxidative biodegradation of oil resulting in carbonate cements with very negative compositions and bacterial fermentation resulting in the positive δ13C cements. δ13C distribution patterns may be used to differentiate Tertiary reservoir sandstones from Jurassic in the northern North Sea, and these regional carbonate cement δ13C datasets allow geologically useful inferences to be drawn from δ13C data from new sample locations.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Present address: Department of Geology and Geophysics, Grant Institute, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK

References

Bailey, N.J.L., Krouse, H.L., Evans, C.R. & Rogers, M.A. (1973) Alteration of crude oil by waters and bacteria–evidence from geochemical and isotope studies. Am. Assoc. Petrol. Bull. 57, 571276.Google Scholar
Conort, A. (1986) Habitat of Tertiary hydrocarbons, South Viking Graben. Pp.159-170 in: Habitat of Hydrocarbons on the Norwegian Continental Shelf (Spencer, A.M., editor). Norwegian Petroleum Society, Graham & Trotman, London.Google Scholar
Craig, H. (1957) Isotopic standards and isotopic correction factors for mass spectrometric analysis of carbon dioxide. Geochim. Cosmochim. Acta, 12, 12133.CrossRefGoogle Scholar
Darby, D., Haszeldine, R.S. & Couples, G.D. (1996) Pressure cells and pressure seals in the Central North Sea. Marine Petrol. Geol. 13, 13865.CrossRefGoogle Scholar
Deegan, C.E. & Scull, B.J. (1977) A proposed standard lithographic nomenclature for the central and northern North Sea. Report of the Inst. Geol. Sci., London, 77/25; Bull. Nor. Pet. Dir. 1.Google Scholar
Dimitrakopolous, R. & Muehlenbachs, K. (1987) Biodégradation of petroleum as a source of 13C-enriched carbon dioxide in the formation of carbonate cement. Chem. Geol. (Isotope Geoscience Section), 65, 65283.Google Scholar
Hertier, F.E., Lossel, P. & Wathne, E. (1981) The Frigg gas field. Pp. 380-391 in: Petroleum Geology of Northwest Europe (Illing, L.V. & Hobson, G.D., editors). Inst. Petrol., London.Google Scholar
Irwin, H., Curtis, C. & Coleman, M. (1977) Isotopic evidence for source of diagenetic carbonates formed during burial of organic rich sediments. Nature, 269, 269209.CrossRefGoogle Scholar
Macaulay, C.I., Fallick, A.E., McLaughlin, O.M., Haszeldine, R.S. & Pearson, M.J. (1998) The significance of δ13C of carbonate cements in reservoir sandstones: a regional perspective from the Jurassic of the northern North Sea. Pp. 395-408 in: Carbonate Cementation of Sandstones (Morad, S., editor). Spec. Publ., Int. Assoc. Sedimentol. 26. Blackwells, Oxford, UK.Google Scholar
McCrea, J.M. (1950) On the isotope geochemistry of carbonates and a palaeotemperature scale. J. Chem. Phys. 18, 18849.CrossRefGoogle Scholar
Newman, M.St.J., Reeder MX., Woodruff, A.H.W. & Hatton, I.R. (1993) The geology of the Gryphon oilfield. Pp. 123-133 in: Petroleum Geology of NW Europe (Parker, J.R., editor). Geological Society London.Google Scholar
Pagan, M.C.T. (1980) Diagenesis of the Forties Field Sandstone. MPhil thesis, Univ. Edinburgh, UK.Google Scholar
Rosenbaum, J. & Sheppard, S.M.F. (1986) An isotopic study of siderites, dolomites and ankerites at high temperatures. Geochim. Cosmochim. Acta, 50, 501147.CrossRefGoogle Scholar
Smalley, P.C., Maile, C.N., Coleman, M. & Rouse, J.E. (1992) LASSIE (laser ablation sampler for stable isotope extraction) applied to carbonate minerals. Chem. Geol. (Isotope Geoscience Section), 101, 10143.CrossRefGoogle Scholar
Stewart, R.N.T. (1996) Regional diagenetic porosity changes in Palaeocene oilfield sandstones, U.K. North Sea. PhD thesis, Univ. Glasgow, UK.Google Scholar
Stewart, R.N.T., Haszeldine, R.S., Fallick, A.E., Wilkinson, M. & Macaulay, C. (2000) Regional distribution of diagenetic carbonate cement in Palaeocene deepwater sandstones: North Sea. Clay Miner. 35, 119-123.CrossRefGoogle Scholar
Watson, R.S. (1993) The diagenesis of Tertiary sands from the Forth and Balmoral Fields, northern North Sea. PhD thesis, Univ. Aberdeen, UK.Google Scholar
Watson, R.S., Trewin, N.H. & Fallick, A.E. (1995) The formation of carbonate cements in the Forth and Balmoral Fields, northern North Sea: a case for biodégradation, carbonate cementation and oil leakage during early burial. Pp. 177-200 in: Characterisation of Deep Marine Clastic Systems (Hartley, A.J. & Prosser, D.J., editors). Geological Society London Spec. Publ. 94.Google Scholar